Injection is a process of sending water or steam, for example, into a well bore to stimulate production in an adjacent well bore. In some well bores multiple zones may be present which present problems of metering the desired quantities of injected fluids into the individual zones from a single tubing or casing string. Injection can require high pressures and flow rates, which means it generally involves high fluid velocities. High fluid velocities are detrimental to equipment such as valves through which the injected material is pumped. Some procedures take production after injection from the same well. In some instances, a gravel pack or other sand control means is used to prevent formation material from filling the well bore should injection be stopped or curtailed, or the well bore placed into a production mode.
Injection has in the past been performed through injection valves, some of which are also known as chokes. These valves were in the past made integral to the bottom hole assembly. If they wore out the string had to be pulled to get them out. Some were mounted into side pocket mandrels. The problem with side pocket mandrels was that additional space was needed in the well to get the side pocket mandrel into the wellbore and that, in turn, required the use of a smaller valve and higher pump capacity at the surface to get the desired flow rates through a smaller valve. Additionally, the characteristics of the formation had to be anticipated when the string was made up so that the layout of several valves that were designed to balance the flow into the formation for injection or in the reverse direction, had to be fixed during string makeup. One alternative to this was to use a series of valves that could be manipulated from the surface through one or more control lines that ran to each valve. The problem with this approach was cost of the various control systems and lack of space in the well for all the control lines that were needed to be able to independently control each valve in attempting to match flow resistance at the valves to formation characteristics to get uniform flow in either direction to or from the surface string. One approach to balancing inflow from the formation, when using many screen sections, was to put a flow resistor together with each screen section when assembling the screen assemblies. Here again, the formation characteristics had to be anticipated so that greater resistance could be disposed where greater flows were expected. The resistance path was a spiral path and U.S. Pat. No. 6,222,794 illustrates that design and several alternatives. Screen sections have come with base pipe ports that could be opened or closed in a variety of ways. These systems were interested in opening or closing a screen segment to start or stop production from a given interval in a zone rather than to be used in balancing flow in a zone. These systems were integral to the bottom hole assembly with some having only open and closed capability while others could hold intermediate positions. Some examples of this approach are U.S. Pat. Nos. 6,371,210; 7,096,945; 7,055,598; 6,481,494 and 6,978,840. U.S. Pat. No. 4,399,871 shows a chemical injection valve with a bypass feature.
What is needed and not provided in the prior designs is a valve assembly that can be run in and secured through the string at a desired location. The valve can be adjusted between fully open and closed while secured without the use of control lines running outside the string. The valve can accommodate injection service and can come with a sand control feature to do double duty for injection and production. Position changes between open and closed and insertion and removal can be accomplished by wireline so that flow balancing can be quickly reconfigured to adapt to variable well conditions. These and other features of the present invention will be more apparent to those skilled in the art from a review of the description of the preferred embodiment and the associated drawings while recognizing that the claims define the full scope of the invention.